List of products in the National Drug Code with proprietary name . This medication is used to improve breathing and reduce the risk of lung infections in people with cystic fibrosis. It is used along with other treatments for this disease (e.g., chest physical therapy, medications, nutritional supplements). Dornase alfa is the same as a substance (DNase I enzyme) that is naturally produced by the body. It works in the airways by decreasing stickiness/thickness of mucus so that it can be cleared from the lungs more easily.